Bomb release rack



Dec 13, 1949 c. THuMlM BOMB RELEASE RACK 6 Sheets-Sheet l Filed Feb. 14, 1945 INVENTOR. CA RL T HUMM A TTgRNEYs HON Dec. 13, 1949 c. THUMIM 2,491,400

BOMB RELEASE RACK Filed Feb. 14, 1945 e sheets-sheet 2 MW# Z INVENToR.

CARL T H UMM BY W4( 'VW' A TTORNEYS Dec. 13, 1949 C. THUMIM 2,491,400

BOMB RELEASE RACK Filed Feb. 14, 1945 6 Sheets-Sheet 5 INVENToR. MRL THI/MIM BY .www

ATTRNEYs DEC. 13, 1949 Q THUMIM 2,491,400

BOMB RELEASE RACK Filed Feb. 14, 1945 6 Sheets-Sheet 4 mi-IM www ATTORNEYS Dec. 13, 1949 c. THUMIM BOMB RELEASE RACK File Feb. 14,. 1945 6 Sheets-Sheet 5 ARL THUMM TTURNEYS Filed Feb. 14, 1945 6v Sheets-Sheet 6 Ck/O /0 Flay# 7 IN VEN TOR. ARL TH UM IM m mmvws Patented Dec. 13, 1949 BOMB RELEASE RACK Carl Thumim, Yeadon, Pa., assigner to I. T. E. Circuit Breaker Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application February 14, 1945, Serial No. 577,831

2 Claims.

My invention relates to bomb release racks, and more particularly to a bomb release rack so designed that it will ensure an accurate, positive and immediate release of the bomb when the bomb release mechanism is operated.

In the design of bomb release racks, it is essential that the release be such that it will function properly for both horizontal lbombing and vertical dive bombing, and the mechanism must be operative under all circumstances and conditions. Further, all of the mechanism must be designed to be confined within the prescribed dimensional limits as determined by the spacing of the hooks on the bombs, the area available Within or on the airplane and the predetermined aerodynamic stability of the plane itself. Furthermore, the bomb release rack must be so designed that it is unaected by extreme variations in temperature, extreme variations in the speed and direction of the airplane, extreme and momentary variations in load owing to rapid turns either during the bombing run itself or during evasive action; and dirt and icing conditions.

Heretofore, bomb release racks have required that the Weight of the bomb operate the release latches themselves. This often led to false operation or, what was much Worse, failure to operate instantaneously at the instant of release.

My invention contemplates essentially that the bomb be supported by two freely rotatable hooks engaging the holding rings on the bomb itself; and that the hooks be maintained in engaged position -by a quick acting latch mechanism which is instantaneously responsive to the action of the operator; and further, that the latch mechanism be positively operated by direct means rather than by the Weight of the bomb.

My invention further contemplates that the individual hooks be separately latched. The latch members may be moved to latching position simultaneously by a tie-link, while the hook members may independently be moved to engagement with the latch members to facilitate the loading of the bomb. My invention, however, contemplates that the latch members and the hooks be simultaneously released. For this purpose the elements controlling the latches are` tied together by the single tie-link. Energy for quick opening of the latches is supplied by a pair of compression springs at each end of the tielink, which vsprings are compressed when the latches are in latching position and which bias the tie-link and the latching members to open y position.

The operation of the compression springs to move the latching members to open position is resisted by a third latohing element comprising a toggle which is extended when the tie-link is moved to the position where the latches are engaged; a latch member supports the center pin of this toggle in the fully latched position. Operation of the bomb release mechanism removes' the supporting latch from the center pin of the toggle and permits the compression springs to operate the tie-link to in turn operate the hook latches to release the hooks. The operation of the compression springs is direct and immediate and occurs instantaneously on movement of the supporting latch out of supporting position.

The hook latchlng elements are located at either end of the tie-link so that the provision of compression springs at either end of the tie-link provides a direct and immediate means for actv ing on the hook latches to free the hook at each end.

My device is so designed that it has a minimum of essential moving parts. These parts comprise the tie-link supporting toggle and its latch and hook latch release toggles at each end of the tie-link and the hooks themselves.

This relatively small number of moving parts i makes possible the utilization of exceedingly strong members within the confined space which is provided and enables the provision of a factor of safety as high as 5 or even better.

My invention further contemplates a simplied release mechanism and a simplified arming mechanism all contained within the bomb release rack itself.

My invention further contemplates a simplified manual bomb release and manual arming means, the mechanism for which is entirely contained within the bomb release rack itself.

A primary object of my invention, therefore, is the provision of a novel quick acting bomb re lease rack useful for horizontal .bombing as Well as vertical dive bombing.

Another object of my invention is the arrangement of a bomb release rack in such manner that individual hook lat-ches are supported in latching position by a third latch, the operation of which results in simultaneous release of the hook latches. Y

Another object of my invention is the arrangement of a bomb release rack wherein force multiplying toggle members are utilized to provide a positive retaining force on the bomb hooks far exceeding any contemplated force which may be Y exerted thereon, and where, nevertheless, on

be instantaneously released irrespective of the position of the plane.

A further object of my invention is the arrangement of a bomb release rack in such a man ner that it will be unaffected by eXtreme variations in temperature or by dirt and ice conditions or by extreme variations in load owing to extreme changes in speed or direction of the airplane.

Another object of my invention is the provision of simplied manual release and manual arming mechanism associated with the automatic mechanism of the bomb release rack. I

These and many other objects of my invention will become apparent in the following description and drawings in which Figure 1 is a longitudinal view of my novel bombrelease rack partly inA section showing a bomb held thereby.

Figure 2 is a View corresponding to that of Figure 1 showing the release position of my bomb release rack. Y

Figure 3 is a View similar to that of Figures 1 and 2 showing the conditions of the bomb release rack in the vertical dive bombing position just after tripping of the release members and just before the bomb has been completely released;

Figure ll is a View corresponding to that of Figures 1 and 2 showing however the loading position of my novel bomb release rack.

Figure 5is a schematic view corresponding exactly tothat of Figure 2 and showing the release position of the bomb release rack.

Figure 6 lis a schematic view corresponding to that of Figures l and 4 showing the loading and bomb retaining position of my bomb release rack.

.Figure 7 is a view corresponding to that of Figure 2 showing however the utilization of indicating means'to signal possible failure t0 operate effectively.

Referring now to Figures l and 2, my novel device is mounted between a pair of opposite side plates II which may be interconnected, crossbraced and secured to the airplane in any suitable manner as, -for instance, by bolts or other securement devices passing through openings I2.

The bomb rack comprises a principal tie-link I4 Vwhich extends between the compression springs l5 and I5. Compression spring I5 bears against the cross piece l? of the bomb rack at one end and at the other end drives an abutting element l8 against the cross piece i9 of the tielink I4. Compression spring l5 accordingly tends to drive the tie-link I4 toward the left with respect to Figuresl and 2.

The tier-link I4 at the other end is connected to compression spring I5 through the Vbell crank lever 26. One end 2| of the bell crank lever 2li is pivotally connected at the pivot 22 to the left hand end of the tie link Ill. The other end 23 of the bell crank lever 22 is pivotally connected at 24 to the link 25 which in turn is connected at 25 to theY link 2l. Link 2l is biased downwardly by the compression spring i6, one end of which bears against a cross piece 28 at the top of the bomb rack and the other end of which bears against the end of link 21.

The downward bias on link 27 transmitted through thelink 25 biases the end 23 of bell crank lever 20 downwardly; this motion is translated into movement toward the left of end 2| of bell crank 'lever 20 thus biasing the tie-link I4 toward the left. Accordingly compression springs I5 and I6 have simultaneous and similar action I The tie-link I4 may be moved from the position shown in Figure 2 to the position shown in Figure 1 by rotation of the knob 30 of screw 3l which passes through the tapped opening 32 in the cross piece 33 of the bomb rack. Screw 3I is connected to the element 3e and has rotational movement with respect thereto but is locked against longitudinal movement withrespect to element 34. Element 34 is connected by the link 35 to the end 3B of link 3l. The opposite end of link 3l is mounted on a stationary pivot 38.

Bell crank lever 39 is rotatably mounted on the stationary pivot 3S. One end 40 of the bell crank lever 39 may be brought to bear against the inner (left hand) surface of the Icross piece I9 of tie-link I4. lThe opposite endY 4I of the bell cranklever 2S extends beneath a lug t2 on the line 3l.

It will now be obvious that rotation of the knob Si) in a direction to cause the screw 3l to move downwardly with respect to the cross piece 33 will draw the connecting element 34` and link 35 downwardly. This will cause the link 3l to rotate in a clockwise direction round the pivot 3S. Lug 42 oi' link 3i accordingly will bear downwardly on the end ci of bell crank lever S9 thus causing bell crank lever 39 to rotate in a clockwise direction and moving the end 4Q of the bell crank lever 32 toward the right. This will result in movement of the cross `piece I 9 and hence of the tie-link I4 toward the right to compress the spring I5 directly. The movement of the tielink l will also result in rotation of bell crank lever 2l] in a clockwise direction to raise the link 2l and compress the spring I6.

The knob 3i) is rotated to move the screw 3I downwardly until the tie-link I4 is locked in position against the bias of compression springs I5 and I6. rihis lock is obtained -by means of the toggle mechanism comprising links 115 and 45. Link is pivoted at one end on the stationary `pivot tl carried between the Vside pieces of vthe bomb rack. The opposite 'end of link 45 is connected by the center pin 48 to the end of link 45. The outer end of link 4S is connected at the pivot 49 to the tie-link I4'.

When the mechanism is in the completely released positi'on of Figure 2, the togglev 45-48 is collapsed and the springs I5 and i6 are extended with the tie-link i4 moved over to its left hand position. When the screw 3l has been moved downwardly to perform the operation above de.; scribed to move the tie-link to the right, the

, toggle ZIE-36 is extended to the position shown in Figure 1 and is supported by the latch member 5l).

The toggle 45-45 is provided with a roller 5I rotatably mounted on the center lpin '43 of the toggle, which roller bears against the left-hand side of the latch member Eil in the 4collapsedposition of Figure 24. When the toggle is extended to the locked position of Figure :1,vth-e latch member 52 moves under the roller Y5I to support the center pin 48 of the toggle 45445 `and prevents collapse thereof. With the toggle i5-'46 locked in the extended yposition or Figure 1, the tie-link lll is now supported in the right-hand position of Figure 1 against the bias of the now compressed springs I5 and l5.

The latch member 59 is pivotally mounted on the stationary pivot 52 and -is biased toward latching position by the c oi-l spring v53, one4 end 54 of which bears against 4the right-hand side oi the latch member 5i) and the other end 55 of which bears against stop 56 on the frame of the rack. The latch member is accurately positioned in the supporting position shown in Figure 1 by the stop 51 which limits counterclockwise rotation thereof under the influence of the coil spring 53 so that, as shown in Figure 1, the latch member will automatically `be positioned to engage the undersurface of roller 5| when the toggle 45-46 is extended.

Since the tie-link I is now supported in the latched position of Figure 1 by the toggle 45-4 and the latch 58, the bell crank lever 39 and the longitudinal screw 3i associated therewith are no longer necessary to support the tie-link I4 in position, accordingly the screw 3| may be rotated back to the position shown in Figure l.

When the screw 3| is rotated upwardly now by rotation of the knob 30, the end 36 of link 31 rises upwardly thus moving the lug 42 of the link upwardly away from the end 4| of the bell crank lever 39, and the bell crank lever 39, by reason of the fact that the end 40 thereof is heavier than the end 4|, may rotate freely counterclockwise away from the cross piece I9 of the tie-link I4. Now, as shown in Figure 1, the only thing that maintains the tie-link I4 in position against compression of springs I5 and I6 is the latch 59 bearing against the roller 5| on the center pin d3 of the extended toggle 5-li6- Should the roller 5| of toggle 45-46 for any reason not be engaged, then the pressure of the springs I5 and I6 to force the cross piece I9 of link I4 against the end 40 of bell crank lever 39 will be felt by the operator as he rotates the knob to raise the screw 3| and that will be an immediate indication to him that the tie-link I4 has not been locked in position by its toggle and latch. As a further indication, an opening 69 (Fig. l) may be provided in the side frame member of the bomb rack, which opening will be cleared only when the toggle i5-46 is in the extended latched position; and the operator will not be able to see the side of the link 45 through the opening 60 when the toggle is fully extended. Now on moving the screw 3| upwardly by rotating the knob 30 in the proper direction, the operator will receive further indication that the latches are engaged if the opening B0 remains clear. 1f the opening 69 is however blocked by the link 45, that will be an immediate indication to the operator that the latch has not been engaged.

In appropriate cases, and where desired, a safety pin may be passed through opposite aligned openings BU in the side frame members of the bomb release rack to prevent any collapse of the toggle 45-46 owing to any cause. The pin through the aligned openings 60 may be left in position until just before the plane takes oit; or in the event that the plane is used simply to transport bombs, the pin may be left in position while the plane is in flight.

Use of the safety pin through the openings 6I! completely de-activates the bomb release rack and makes it impossible to release bombs for any cause; and accordingly it will be used only on extreme, rare and unusual roccasions-such, for instance, as ensuring that the bomb release rack will be completely de-activated while planes are on the flight deck of an aircraft carrier or under other circumstances where the accidental operation of a bomb release rack must be positively defeated.

When the tie-link I4 is moved from the posi- 1,the latch members 10 and 1|, which engage respectively the bomb hooks 12 and 13, are moved to latching position. With respect to the latch member 10: the movement of tie-link I4, to the right, moves the pivot 22 to the right and accordingly moves retaining link 15 connected at one end to the pivot 22, to the right. Retaining link 15 at its opposite end 16, is connected to the compression spring link 11, the opposite end of which is at 18 connected to the latch 10. Accordingly movement, to the right, of the retaining link 15 tends to move the spring link 11 to the right; since, however, the latch member 10 is pivotally mounted on the pivot 19, the spring link 11 is forced to move downwardly and to the right on movement of the retaining link 15 to the right. Consequently, this operation rotates the latch member 19 from the position shown in Figure 2 to the position shown in Figure 1.

The latch member 10 has a pair of extensions 8| and 92 on the opposite side of the pin 19 from the latch portion. The extension 8| engages the stop member 84, as shown in Figure 1, when the latch 113 has reached the exact latching position. Any further movement of the tie-link I4 toward the right after the latch 10 has been stopped in 'the exact latching position is taken up by compression of the spring link 11. The extension 82 of the latch member 10 is arranged so that it is in the path of movement of the abutment 8B on the link 2|. When the bomb release rack is tripped and the end of link 2| is moved rapidly toward the left, as hereinafter described, the abutment 85 will strike extension 82 of the latch 19 and impinge a hammer blow on the latch 10 in a counterclockwise direction to move it from the position of Figure 1 to the position of Fig-Y ure 2.

The latch member 1| operates in exactly the same manner as does the latch 10. The link 2| is pivotally mounted at one end on the pivot 49 and at the other end is pivotally mounted on the stationary pivot 19. Pivot 49 on the tie-link Id is connected by the retaining link 15 to the spring link 11', which in turn is pivotally connected at 18 to the latch 1|. Accordingly, retaining link 15 and spring link 11' act in the same manner as do links 15 and 11 above described.

The latch member 1| is provided with an extension 8|' which bears against the stop 84 to predetermine the exact latching position of the latch 1|.

Link 2|' is provided with an abutment 86 which strikes a hammer blow on the extension 82 of the latch 1| during the opening operation again as previously described in comiection with the link 111.

In the operation of my device, when the tie-link Iii is moved from the position of Figure 2 to the position of Figure 1, then the latch members 1I! and 1| are moved from the position of Figure 2 to the position of Figure 1 while the bomb hooks 12 and 13 nevertheless remain in the position of Figure 2.

The bomb |00 cannot be mounted on the bomb rack until the knob 30 has been moved upwardly by'rotation of screw 3| to move it upwardly. This, as above described, provides a test of the proper locking of the latches.

It is now necessary to engage the hooks 12 and 13 with the latches 10' and 1| respectively in order that the bomb may be loaded. Accordingly, the bomb is lifted up toward the bomb rack, as

shown in Figure 4, by a cable and hook |0| engaging the loading ring |02- of'thebomb. As: theV winch is operated to raise, the bomb, the rings |04 and |03 are broughtY up into juxtaposition with.

the hooks 12 and 13 respectively.V

With the latches in they charged position, as.

shown in Figure 5, but with thel hooks 12 and 13 disengaged and remaining in the position of Figure 2, Vthe bomb, of course, cannot be held.

However, when the hooks 12 and 13 are` moved to the, fulllocked position of Figure 1,Y the bomb cannot be moved out of the, holding position be.`

cause. of the great forcerequired to release the;

hooks 12 and 13.

Accordingly, my device, particularly by the use of the spring links 11 and 11', provides for a means of manipulating the. hooks. 12 and` 13 between the full open position of Figure 2 up to almost the full locked position. of Figure 4 even though the latch members 10 and 1Ir and the main latch 50 are engaged.

Referring now to hook 12 of Figure 4, it will be seen that this hook may be rotated'readily about its pivot from the position shown in Figure 2 to the position shown for hook 12 in Figure 4, and through that position to the full latch position shown for hook 13 in Figure 4. As the hook 12 is rotated about its pivot H0, thev latching roller il I thereof bears upwardly against the undersurface of the latch and causes the latch 10 to rotate counterclockwise about its pivot 19 compressing the spring 1 1 uritil the latch roller engaging surface H2 of the latch 13 bears against the surface of the roller H Further rotation of the hook 12in a clockwise direction causes the roller to move further to the right with respect. to the; latch Vengaging surface ||2 of the latch 10 until the latch engaging surface H2 is tangential with the surface of roller i l-that is, until the hook is in the latched position of hook 13 shown in Figure 4, where any movement of the hook counterclockwise is blocked by the latch engaging surface H2.

Thus, when the bomb is loaded, as previously pointed out, the bomb |00 is hoisted up toy a point Where it is adjacent to the hooks 12 and 13 and the rings .|04 and |03 are positioned im,- mediately beneath the hooks 12--13 respectively. Hooks 12 and 13 are individually rotated clockwise around their pivots ||0 until a deflnite detent. action is felt, at which time the hooks. are almost closed with suicient room left for entry of the rings |94 or H33. This detent action is felt when the lower edge of the latch surface of latch 10 passes a line on the surface of lthe roller extended through the pivot ||0 and the pivot H of roller (Figure 4) The bomb rings |04 and I 03 are then positioned in the slots of the hooks 12 and 13; and further lifting of the bomb |00 by the winch attached to cable |0| will now force the hooks further upwardly, rotating the hooks further in a clockwise direction and causing the hooks to move from the previously mentioned detent position to the full latched position of hook 13 in Figure 4 or to the completely latched position -of Figure l.

From Figure 4 it will be seen that the hooks may be latched independently of each fotherthat is, the bomb |00 may .be raised and the ring |03 completely secured by the .hook 13 before the hook 12 is positioned for engagement with the ring |04.

By this means therefore, the bomb may be readily and automatically loaded and the vhooks f generally indicated `at |20.

theirl movement. This is a further indication as.

to the latch condition of the bomb release rack.

After the bomb is loaded in the position of Figure, 1, a further test of the condition of the hooks is obtained by loosening theV winch cable 0| slightly. If the latches are unset for any reasom the bomb. will fall out of the hooks since the hooks willengage the bomb only when thev latches are fully set. If thebomb stays in the hooks, then the winch cable |0| may be released from the, loading ring |02.

Thus summarizing, there arefour ways at least in which the bomb release rack may be tested for its latched position before the bomb is nally secured in the rack. First, on rotation of knob 33. upwardly, the operator Will be able to feel, simply on rotation of this knob, whether or not the spring I5 is pressing against the end El of bellcrank lever 39. Second, the aligned holes 50 in opposite sides of the rack frame will be cleared only when the toggle IE5-43 is fully eX- tended toits latched position. Third, the hooks 12 and 13 may be rotated freely around their pivots H0 and H8' between the full open and full closedA position if the latches are not engaged; if the latches are engaged, then, as shown in connection with hook 12 of Figure 4, manual ro` tation of the hook is resisted by the latch member. Fourth, whenl the bomb is in loaded position, a slight release of the winch cable |0| will serve as a nal test for the latches.

Immediately subsequent to loading or even after latching and before loading, a safety pin as previously described may be passed through opposite openings 50. Removal of this safety pin prior to take-olf of the plane serves as a final test for the latched position. It is obvious, of course, that a cable or other device may be attached to the safety pin so that the safety pin mayv even be removed during flight.

The release of the bomb from the hooks 12, 13 is accomplished by the release mechanism The release mechanism comprises a suitable housing |2|, preferably a ,soft iron casting bored at |22 to provide a housing for.solenoid .coil |23. A soft iron rod |24' is mounted, inV the housing in the interior of the coil |23 to provide an appropriate magnetic path cooperating with the solenoid plunger |25. Plunger |25 is provided with an annular recess at |26 to provide a space for dirt andV ice particles so that they will not jam or freeze the solenoid mechanism.

Energization of solenoid coil |23 by closing of the appropriate circuit will cause an attraction of the plunger |25 to close the gap and move from the Figure 1 position to the Figure 2 position.

Plunger |25 is :connected by the pin |28 to the `link |29 which carries a latch engaging roller |30 at its opposite end. Link |.2S` is controlled in its movement .by the guide link I 3|, one end of which is pivoted 'on the same pivot as the latch Unless the principal latching toggle |35- v engaging roller |30, and the opposite end of 'which is pivoted on the stationary pivot |33.

Operation of plunger |25 to the left (with respect to Figure 1) by energization of the solenod coil |23 will cause the roller |30 to strike a hammer blow against the lower end 50 of the latch 50. This will cause latch 50 to rotate clockwise and move out from under the roller 5|. The toggle 45-46 will no longer be supported and will accordingly collapse owing to the bias of the compression springs I5 and 6 (compression spring I5 pushing on the tie-link I4 and compression spring I6 pulling'on the tie-link I4, both operating in the same direction).

As the tie-link I4 now moves towards the left under the influence of the springs I5 and I6, the links 2| and 2|' are driven toward the left. The abutments 86 and 86 respectively of the links 2| and 2| will now strike smartly against extensions 82 and 82 of the latches 10 and 1| respectively. The hammer blow on these latches 10 and 1| will cause them to move smartly from the latched position of Figure 1 to the release position of Figure 2, thus releasing their engagement with the rollers III and III' of the hooks 12 and 13. There will now be no resistance at all offered to counterclockwise rotation of the hooks 12 and 13 about their respective pivots |I0 and H0. Accordingly, the load of the bomb will promptly rotate the hooks 12 and 13 about their pivo-ts I I0 and I I' and the bomb will be released as shown in Figure 2.

Spring stop members |40 and |40 are provided to absorb the shock of rapid rotation of the hooks 12 and 13, respectively, and are struck by rollers III and of the hooks on completion of the release of the bomb as shown in Figure 2.

It will be noted that during the release operation, the pressure of the springs I and I6 is not alone relied on, butl rather the device is so arranged that the kinetic energy of a hammer blow is obtained. Thus, the latch release roller |30 is not initially, in the position of Figure 1, in engagement with the end 50 of the latch 50 but rather is substantially spaced therefrom. As the plunger |25 is attracted within the solenoid, substantial kinetic energy is stored up and the roller |30 is arranged to strike the end 50' of the latch immediately before the completion of the movement of the solenoid plunger |25 when it is moving at its greatest speed, and thus to strike the latch end 50 a sharp hammer blow. This hammer blow exerts a force on the latch member which is a compound of the attractive force of the solenoid coil |23 plus the kinetic energy of movement of the armature I 25.

Similarly, the release of the latch members and 1I for each of the hooks 12 and 13 is achieved by a hammer blow in which the force of the springs I5 and I6 is compounded with the kinetic energy of movement of the tie-link I4 and the associated elements.

Thus, in the latched position 'of Figure 1, the abutments 86 and 86 are spaced from the extensions 82 and 82' of the latches 10 and 1|. These abutments 86 and 86' do not strike the extensions 82 and 82 until the tie-link I4 has moved for some portion of its full distance At this time, the springs are sufliciently far from the end of their stroke to exert maximum energy while the kinetic energy of movement of the tie-link I4 is additively Vused to move the latches sharply out of engagement. Accordingly, the operation of the release mechanism is positive and direct.

While the compression springs I5 and |6 are suicient to ensure a full opening operation, the spacing of the elements to utilize a series of hammer blows to operate the latches ensures a multiplication of force which will positively open the latches irrespective of the Weight of the bomb.

In order further to ensure release of the hooks 12 and 13, the rollers III and III are mounted in needle bearings having a minimum co-eiilcient of friction to ensure that the latches 10 and 1| may move freely with respect to the rollers when they are struck the hammer blow as above set forth.

Thus, it is obvious from all of the foregoing that the latches are positively tripped by mechanical means irrespectivepf the Weight of the bomb and that the bomb weight plays no part in tripping the latches. After the latches are tripped, the bomb need merely rotate members 12 and 13 on their needle bearings as it falls out. Since these members are so balanced that they tend to assume the position of Figure 2, lthe bomb need perform no work even to rotate them.

On de-energization of the solenoid coil |23, the apparatus is so designed that the release mechanism will re-set itself to the original position of Figure 1 in preparation for a re-setting of the latches. This re-setting operation of the release mechanism is accomplished by compression spring |50 mounted in a recess |5| of the housing I 2| of the solenoid and bearing at one end against the base |52 of the recess I 5| and at the opposite end bearing against nut |53 on the rod |54. Rod |54 is pivotally connected at |55 to the link |56 which is rotatably mounted at |51 on a stationary pivot secured to the rack. Link |56 at its lower end is pivotally connected to the pivot |28 between the solenoid plunger |25 and link |29. Accordingly compression spring |50 which biases the link |56 in a counterclockwise direction biases the pin |28 toward the right and tends to drive the solenoid plunger |25 toward the right or toward the non-tripped position of the solenoid shown in Figure 1. Link |56 is lprevented from rotating too far to the right by the stop 58. Accordingly, immediately on de-energization of the coil |23 of the solenoid, plunger |25 is moved back to its non-tripped position.

A manual trip mechanism is provided at |69 which comprises essentially a pair of arms I extending upwardly from link |56 on the upper side of its pivot |51. The arms |60 carrry between them the Weight |6| which is rigidly connected thereto by the pin |58 and the spot welding |59. The Weight I6| serves as a counter-balance to that portion of the link |56 that is below the pivot |51. This balancing prevents involuntary operation due to sudden changes in motion of the plane.

The cam following surfaces |64 of the arms |60 are arranged for engagement with the cam roller |62 which is spring biased by the coil spring |63 (preferably of flat beryllium copper) to the non-trip position shown inFigure 1.

A cable is wound around a portion of the cam roller |62 and is led around guide roller |66 through the top of the bomb release rack to the manual release ring |61 which is held in position by a suitable stop |68. Pulling manual release ring |61 upwardly will pull up the cable |65 to rotate the caml roller |62 clockwise and bring the raised surface thereof against the cam follower |64 to force the cam follower |64 and the arms |60 toward the right and therefore to cause the entire link |60-I56 to rotate in a clockwise direction around its pivot |51. This will, through the .pivot |28, draw the link .|29 toWard'the'left -With'respect to Figure l, thus `pulling `the tripping element |30 against rthe extension 50 of the latch 56 and trip the device open/as'above set forth.'

Suitable rrcontrol means' may lbe vprovided as required. Thus, for instance, .a transfer switch HD may be provided, so .designed that it will be operated by the link mechanism |14|15 .in the following manner. When'the control solenoid ,plunger |25 is actuated andlink |56 is moved yto the leftwithrespect to Figure 1, the links v| 'I4-415 will break upwardly at their pivot |15. Collapse 'of the toggle 45--45 due to tripping actionplaces Ythe roller 48 in 'the position shown inFigurefZ. When the solenoid plunger |25 is released and `the lever v| 56 returns to itsnormal position, thereby straightening out the `toggle Vid-|75, Vthe 'right hand end of which is prevented fromzmoving by the appearance of roller 48 .in the rspace once occupied by the roller |71, the left hand end of the linkage |19 moves :forward to actuate the switch plunger This double lposition of .the

fend |79, lof the toggle |14-||5,is provided for by vthe elongated holes |18.

Since the links |14-|15 are straightened rout .only after the solenoid plunger |25 and the link v|55 are-moved to the right, Vdue to the de-energi- Zation ofthe solenoid |23, it becomes obvious .that the transfer switch cannot be actuated .until after vthe bomb Vhas been released, lthe toggle mechanism l5- .46 collapsed and the solenoid |23 `rie-- energized;

:Other .indicating :devices may vbe 'provided as required. Thus, 'for iinstance, 'an appropriate Yswitch operator orplunger may beprovided'at |81 (Figure '7) `to Vindicate that the hook .12 -is in the full lat-cned position'. This will continuously'indicate tothe .bombardier the condition of the bomb .rack and willprovide vhim Vwith an indication of 'the release of the bomb. Preferably the switch 8| should close the circuitltoia light on the in- 'strument panel so that there will 'always .be a .constant positiveindication of Ythe fact `that the bomb is inthe rack,:and.the extinguishment .of the light will indicatetherelease.ofthe bomb.

Should the bomb release rack, when tripped, jam for any reason as shown 'at the left .hand end "of Figure 7^, then switch |81 `will provide-an immediate indication `of .thislfact Vlt vwill be noted Vthat .the surfaces 'm2-|84 -(Figure 2) of the recesses IBD-'|90' respectively are disposed at an .angle fof 15 degrees from the vertical. These surfaces |82--.|84 cooperate with the bombing hooks |2-`|3 .respectivelyto form `the above .mentioned recesses within whichfthe u.

Vbomb loading rings VA"i3-|114 are captured. Inas- `much as the-surfaces ri v82--i` 841wi1l bearthe entire weight of the bomb in the almost verticalfdive Abombing position, shown in Figure 3, it .is .desirable to provide the 15" vslant since at Y.this .angle vthe bomb will be sure to overcome any friction regardless of the lbom-loing angle'of the plane and the release of the bomb will be ensured,fregard .less also'o'f thebombing langle of the bomb rack fat the time of discharge.

The abutments |9|--|`9| are provided .tovgive additional rigidity to lthe sides lH .of `the fb'omb rack and also providea broad .smooth surface on which the loo-rnb loading rings :w3- |04 slide. The abutmentsV ISI-49| are suitably secured between the side frame .members by :the :cross .bolts `|951! and provide -a surpport ifor the bomb hook shock-absorbing springs |40.

.As will be obvious imma-comparison of Figures 1 and 3, my bomb rack willoperatc eiectivelyfto 12 lrelease thebomb in'any position from the' steepest possible climbing angle to a vertical diving position.

One ofjthe primary problems which occurs in equipment, such as bomb release racks mounted on the outside of airplanes, is the protection of the equipment against dirt and ice. It will be .noted here that essentially two types of enclosure are-used. Where possible, as in the ease of the solenoid release mechanism, the plunger and Vother members contained in the housing |2| are Ycompletely enclosed lwith van appropriate recess |-26provided inthe plunger |25 to provide a space for any dirt or ice which may get in Vand thus causethe jamming of the parts. When it is not possible to enclose the parts completely, then the .parts are left entirely in the opento permit the dirt to drop out or be blown away.

Accordingly, the materials used must themselves be inherently self-protecting with respect Vto corrosion, dirtrand other influences to which lplane parts are subjected. Thus, the materials are Ychosen to give the least possible galvanic action. To accomplish thiswherever possible, all working parts are made of stainless steel. The various pins, for example, are of heat-treatable `non-.galling type #416 rustless iron, as defined in the Steel Products Manual-Stainless and Heatresisting Steels- Section 24, July 1947 issue of the American Iron and Steel Institute, 350 Fifth Avenue, New York l, N; Y., and .the latches'are made of type #440-F Ias defined inthe Steel vProducts Manual-Stainless and Heat-resisting .Steels-Section 24, July 1947 issue 'of the Amery :ican Ironwan'd Steel Institute, '350 Fifth Avenue,

New York l', N. Y., which'can be hardened to 60 Rockwell C. The bearings throughout have one velement `of homogeneous :and the other coacting `element of heterogeneous structure, so as to prorvide for boundary lubrication. Where loads revquireitalnminum bronze bushings are used, this being v'the only place where galvanic action Vmay occur. HoWever, when 'covered with any low temperature lubricant, the effects of this action would be at'a'minimum. Where'very light loads are'encoun'tered, :as in the arming linkage (hereinafter described) vplastic bushingsV yare used.

`A careful analysis of .all the linkages with an allowance of an extreme coefficient of friction of v25% will show that the parts `are suciently strong Vand rthe leverages suiciently large to ensureimaxmum safety Lin operation. That is, for a positive release .of the bomb to hold the size of vthe nperating mechanism to reasonable proportions, it isnecessary to use needle bearing rollers at I||, to bear against the Iconcentric latch surfaces. The'use of ordinary rollers with a frictional 'coeilcient of..25 wouldrequire more force .and a coillarger than thespace available to limit the temperature rise. While the cofficient of friction of a .needle bearing is below 1%, the design of the device herein disclosed was ybased on a value .of 5% giving the factor of safety of 5 at the latch itself. In all cases, the bomb load on the hooks was calculated on the basis of 5G, and .thismultiplied by yaninherent factor of safety of 5 at the latch results in la force 25 times that required to disengage the bomb-retaining latch ilnderstatic conditions. .In other waords, once the .latchesare lockedin position, the factor of safety is 25.

Toreduce the effects vof seizure, sticking 'and friction-'al1 parts were `p'ivotecl wherever possible, and rectilinear .motion was avoided. Therefore, the pnlypoints where rectilinear motions occur are in the solenoid plunger and compression springs.

It will be evident that the design herein disclosed was so contrived that dimensional accuracy is notI too important and has only a minor effect on the operation. Essentially, this is achieved by the utilization of the spring links 'l1 and Tl cooperating with the stops 84 to position the latch members 'l0 and 'i9'. The width of the latch roller engaging face H2 of each of the latch members provides for a margin of safety even after substantial wear has occurred. This is particularly so since the roller by reason of its angular position with respect to the pivot ||ll must rst move upwardly further into engagement with .the latching surface ||2 before it can move downwardly out `of engagement. Accordingly, misalignments in assembly and changes in dimension due to wear or replacement of parts should, within reasonable limits, have no substantial effect in the operation of the device. For example, scaling the device on -a -basis of 14" between the bomb loading rings |03 and |94, surfaces H2 of the latches 'i9 must be moved a full M3 before tripping occurs. Misalignment of the latch parts to a large fraction of this amount will not affect operation.

In choosing favorable mechanical advantages, long wheelbases were utilized where lpossible, and, as above described, latches which did not depend on hair-trigger action Vwere utilized. Accordingly, the necessity for extreme accuracy was avoided.

In the operation of the device, as previously described, since the bomb weight is not used to open the release mechanism, the marmer in which the bomb weight is applied has no effect on the release action. Therefore the smoothness of the hook surface is immaterial and any indentation due to softness or brinelling as a result of vibration has no eiect on the operation.

The springs l5 and IE required to trip the bomb produce about times the amount of energy necessary to overcome the friction at the rollers iii caused by the weight of the bomb. In order to hold `the spring, the force of the spring is first reduced by means of the toggle l5-46 set considerably below the friction dead center to avoid failure due to the action of friction. This toggle is prevented from Icollapse by the dead center roller latch 5G which in turn can -be released by the action ofthe solenoid release mechanism. It should be noted that the force on the latch co-mes from the coil spring 53 and therefore is constant and is entirely independent of the weight f the bomb or the position of the rack.

Another feature of the design is that two release -springs I5 and iB are used, one at each of the opposite latch positions 19 and l I, so that the long link lil connecting the two release mechanisms is under little stress during the release operation. The link I4 is used, first to ensure that the springs l 5 and I6 will be charged simultaneously, and secondly as a tie so that both mechanisms work together.

As previously pointed out, the solenoid operates through a linkage which strikes the release latch with a hammer blow to ensure positive action, although the design is such that enough force is available for operation with a slow lpush. The los motion thus made available however, permits the solenoid plunger and its linkage to vibrate with a considerable amplitude withoutI resulting in release.

'Ihs spring 53 on latch 59 is calculated to produce a minimum frequency of cycles per second while the reelase mechanism is balanced by the weight |6| suilicient to withstand 20G in the direction of braking of the plane without resulting in release.

Accordingly all necessary safety factors have been considered, and my novel device is therefore so arranged that it will not trip unless the solenoid coil |23 is energized or the manual pull ring |61 is pulled, while nevertheless the bomb release mechanism will be instantaneous and positive in operation on energization of the solenoid coil |23 or on pulling of the manual pull ring 61.

In Figures 5 and 6, I have shown the operation of my novel bomb release mechanism schematically. The Figure 5 schematic position is exactly like that of Figure 2; while the Figure 6 position shows the parts after they have been moved to the position of Figure 4 in which the latches are all in the proper bomb retaining position of Figure l, but in which the hook members have not yet been fully moved to bomb retaining position.

These schematic illustrations illustrate the simplicity of my novel bomb release rack, the minimum of working parts involved, and the fact that the release mechanism is completely independent of the bomb itself for its operation.

My novel bomb rack mechanis-m includes an arming mechanism indicated Igenerally at mounted in the housing |86 carried between the side frame members of the bomb release rack. The housing includes a space for the nose arming solenoid coil |88 and the tail arming solenoid coil |89. Solenoid plunger |89 is provided to coact with the solenoid coil |88, and a similar solenoid plunger is provided to co-act with the solenoid coil |89. The solenoid plungers in the arming mechanism have the same lform as the solenoid plunger |25 of the release mechanism, having an appropriate recess to provide for the collection of dirt and ice without jamming the solenoid plunger against movement.

Oil impregnated felt washers |92 are provided around the solenoid plungers to prevent, as much as possible, the collection of dirt inside the housing.

The solenoid plungers for the nose and tail of the arming mechanism are connected to the blocking levers IBS-|81 which are pivotally mounted at |94 and have blocking surfaces |95- IS5'. These blocking surfaces |95-l95 when properly actuated cooperate with the ends |95- |9`| of the hooks ISB-|99 respectively to lock the hooks and prevent the arming cables 292-293 from slipping free from the hooks 2l`i9--29I respectively.

When the solenoid |38 is energized and its plunger |80 is moved upwardly, it will cause the blocking lever |83 to rotate in a clockwise direction and prevent the hook |98 from rotating about its pivot by blocking the end |95. This action will cause the arming cable 202 to remain captured Within the hook |98 and thus arm the nose of the bomb when it is released. In order to arm the tail mechanism of the bomb the solenoid |89 is energized and its plunger will cause the blocking element |81 to rotate in a counterclockwise direction and prevent the hook |99 from rotating about its pivot by blocking the end |91. This action effects a positive lock for the hook |99, prevents the arming cable 293 from slipping free, and thereby arms the tail of the bomb.

It is obvious from the above description that should it be desirable to arm both the nose and tall of. the bomb at the same time that both the solenoids |88- t89 must be' energized. Conversely it follows that should' it be necessary to release. the bomb in a friendly' area, neither solenoid should be energized so that the arming cablesl may pullV free from' their respective hooks, the' bomb dropping as a dud.

The manual arming mechanism is comprised of two levers 2|0-2 H3 mounted on opposite sides of the arming mechanism. These levers are pivotally mounted at 2| and connected by the Wires 2|2.-2|'2 to the blocking elements l-Il respectively. Raising the' leverllil tightens the wire 2.52 and thereby rotates the blocking lever |83` in a clockwise direction to lock the hook ist as described in ther solenoid operation. Lever 2 l0 and Wire 2|`2 will similarly rotate the blocking lever |81 to prevent the hook |99 from opening. The leverv 2|' has a cam following surface Zia which engages the cam roller Zit, which cam roller has' substantially the same form and operation as the cam. roller |62 of the release mech anism andvis connected by an appropriate cablato the manual arming ring 2|.

Rotation of the cam-roller 2|6 will cause the cam face 2|3 to. raise the lever Zl and actuate the blocking. mechanism |83 as above described, Afurther rotation of the cam roller 2|6 causing the cam surface 21'4 to raise the lever Zit (on the opposite side. of the arming mechanism, not shown) and actuating; the blocking lever E87,

Y manually arming both the nose and tail of the bomb..

An examination o'f the device will show that the maximum space is available for the arming' mechanlsm coil so as to provide the largest amount of copper for the coil and the largest radiation area.

rIhe iron magnet frame of the housing consists of a single rectangular. blockv with cavities machined in it for the solenoid coils. It fits snugly between the side walls of the rack to which it is bolted and pinned in any suitable manner. This gives the best transfer of heat and increases rigidity of the rack during loading.

To maintain the eicency of the solenoids during their life, everything in connection with the moving parts, including the pole piece, armature, coil springs, and linkage, are made of stainless steel of the proper grades. This eliminates the possibility of galvanic action, corrosion and the deterioration or aking ofY plated finishes which would have to be used with soft iron.

In the foregoing Ihave described my invention only in connection with preferred specific embodiments thereof. and the operationr of the elements of my invention in connection with the specinc 16 descriptions thereof.. Since matig/'variations and modications of my invention should now be obvious to those' skilled in the art, I prefer to be bound not by' the specic disclosures herein set forth but only by the appended claims.

I claim:

1. In a bomb release rack, a plurality of freely rotatable members for engaging the holding rings of a bomb, each of said members having a pivotally mounted roller, latch mechanism for controlling said members, each of said latch mechanisms being pivotall'y mounted and in tangential engagement with its associated roller, the pivots of each roller and its associated latch mechanism being in a straight line through said tangential engagement, positively operating means for operating said latch mechanism to free said rotatable members from said latch mechanism, said rotatable members thereupon being freely rotated independent of the bomb to a position at which the members dol not engage the holding rings of the bomb.

A 2. In a bomb release rack, a plurality of freely rotatable members for engaging the holding rings ofV a bomb, each of said members having a pivotally mounted ro-ller, latch mechanism for controlling said members including toggle mechanism normally held in locked position, each of said latch mechanisms being pivotally mounted and in tangential engagement with its associated roller, the pivots of each ro-ller and its associated latch mechanism being in a straight line through said tangential engagement, means for releasing said toggle, positively operating means comprising a spring member for operating said latch mechanism to free said rotatable members from said latch mechanism whensaid toggle is released, said rotatableV members thereupon being freely rotated independent of theA bomb to a position. at which the members do not engage the holding rings of the bomb.

CARL THUMIM.

REFERENCES CITED The following references are of record in the le of this patent:`

UNITED STATES PATENTS Number' Name Date 1,382,307! Mayerson: June 21, 1921 1,500,973 Wearham July 8, 1924 FOREIGN PATENTS Number Country Date 496,953 Great Britain Dec'. 8, 1938 497-090.' Great' Britain De'c. '7. 1938 

